Re: better msleep for drivers

From: Jeff Garzik
Date: Wed May 21 2008 - 11:25:41 EST

Pavel Machek wrote:

Still longer term I suppose there's really no way around having accurate
sleep functions and it's probably better to start testing earlier than later.
No objections, but we should not do that with a stupid msleep
replacement interface; instead we should expose a flexible in kernel
variant of hrtimer_nanosleep() which lets the user utilize
ABS/REL_TIME and the different clocks. A msleep helper can be built on
top of this very easily.

While you are at it... it would be cool to have

'mdelay(2500 msec), but it is okay to wait 100msec more' -- type
interface, so we could use that for nohz benefit.

Currently, mdelay is 'it is okay to wait 10msec more' interface, and
it would be nice to have that explicit.

eh, I think you transposed mdelay with msleep?

msleep() is the "it is okay to wait longer than I said" interface, not mdelay(). mdelay() has always been non-sleeping and exact (as much as the delay loop allows)


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